Both women know the gut-wrenching strain of Olympic failure. Both have enlisted sports psychology as a major weapon in London.

Now rivals Shanaze Reade and New Zealand's Sarah Walker will battle each other to turn disappointment into delight in the women's BMX competition.

Walker's main rival Reade insists she has matured since crashing out on the final bend at the 2008 Beijing Games and can handle the expectations of competing in front of a demanding home crowd.

The British hopeful, one of the faces of the London Olympic Games, suffered heartache four years ago as pre-event favourite, when she tried an audacious move in the final and clipped the wheel of eventual champion Anne-Caroline Chausson of France.

A teenager at the time, Reade was pilloried by some sections of the British press. She now feels much better prepared for her London Olympic assault which begins with the seeding run on August 9, with the final the following day.

Such was her level of disappointment at the Beijing Games, she fleetingly considered retirement. After acknowledging that "I didn't know what it took to be an Olympic champion", she sought the help of Dr Steve Peters, British Cycling's sports psychiatrist.

Peters has worked with a raft of top British athletes including Sir Chris Hoy, the four-time Olympic track cycling gold medallist, and four-time world snooker champion Ronnie O'Sullivan. His role is simple - to get inside an athlete's head and control the irrational side of the brain that he terms "the chimp". For Reade, the link has been invaluable.

"Steve has helped me understand why and what happens in the brain and how to control my emotions," explains Reade. "The female mind is very much controlled by how you think emotionally. But as an athlete, you should never compete off emotions, but facts. Steve has played a massive part in getting me ready for the Olympics.

"I've grown up a lot and matured in many ways, which needed to happen," admits Reade. "I was only 19 at the last Games - it was hard to know everything and be everything at that age. Now, I take it in my stride. It is all about process rather than outcome."

A star of a major pre-Games TV advertisement in the UK and with her own online video show, Reade is one of the most high-profile names in a stellar British Olympic squad which will expect to win a glut of medals in London.

Based in Manchester, where she is training on a newly built track, Reade's confidence was bolstered from winning the test event at the London BMX circuit in Olympic Park - finishing one place in front of Walker - last summer.

Walker also knows the burden of expectation after finishing fourth in Beijing in front of family, a medal-thirsty media corps and an Olympic build-up which had long singled her out as a strong medal hope.

After promising so much in the heats, she failed to deliver in the final and, back in 2009, her coach, Ken Cools, said: "She needs to be there for the right reasons - she needs to be there because she wants to win a gold medal, not because her country wants her to. If you don't want it, it is hard to get to the front of the pack."

Cools, a straight-shooting Canadian, had been involved in the sport for 26 years and rated Walker as "the most gifted BMX rider of her time" but said mentally, she still had work to do.

"She has it; she just needs to find it," said Cools. "It's my job to help her find it. I tell my riders, 'you have to get a bit more mongrel in you.' BMX is a vicious sport. We are sprinters but, unlike sprinters on the track who run in a straight line to the finish, you have to battle with other people in your way. You have jumps, you have turns, you have elbows in your face and you have to fight through it. You have to be tough."

Walker admitted at the time she had a reputation for being too nice. "It has affected me in a lot of races," she says. "It used to be a huge weakness, that I was too nice. It was known that if you went into a corner with me, I would probably back off."

Now, after sessions with sports psychologist David Galbraith, she told one interviewer: "It's just being confident and believing in yourself and being courageous. The most important part is the mental side. When you get to the Olympics, everyone is fairly even and the difference will be who can perform at their best on the day. It might not be the strongest and fastest."